Abstract

Concrete pavements for underground mining are in service under very aggressive exposure conditions(heavy loads and chemical attacks), which reduce their service life and affect mining productivity.Aiming to improve the concrete’s performance, the combined use of silica fume, nanosilica, andpolypropylene fibers was investigated. While each of these materials contributes independently toimproving concrete performance, the similar chemistry of nanosilica and silica fume and the considerableworkability loss by using each of these materials could negatively impact the concrete properties whenused together. Therefore, it is necessary to demonstrate the synergy of using these three materialstogether, and quantify their relevance in the concrete response. In comparison to the control mix, theconcrete mixes with the combined additions showed an average improvement of i) 17% of compressivestrength, ii) 23% of splitting strength, and iii) 22% of flexural strength, iv) 200% of the surface resistivity, v)212% of the abrasion resistance, and vi) 158% of less sulfate expansion. As the numerical modelling of theresults indicated a statistically significant interaction between the independent variables, it is proposedthat the silica fume, nanosilica, and fibers act synergically, enhancing the underground miningpavements.